Prior Art Statement
The following publications are representative of the most relevant prior art known to the applicant at the time of filing the application: U.S. Pat. Nos.:
1,973,441, Sept. 11, 1934, K. Moers et al;
3,765,300, Oct. 16, 1973, K. M. Taylor et al;
4,081,284, Mar. 28, 1978, S. Prochazka;
4,104,062, Aug. 1, 1978, G. Q. Weaver.